The invention generally relates to a beverage, or the like, for all forms of endurance exercise, work and recreational activities requiring or benefitting from fluid replacement during the activity. In addition, the beverage and its unique formulation can be used for rehydration after the activity or exercise is completed. More particularly, the invention is directed to the use of the specific amino acid, glutamine, as an essential component for a sports beverage.
Oral replacement solutions have been well demonstrated to enhance endurance performance by providing water to maintain hydration status, electrolytes (primarily sodium) to avoid disturbances such as hyponatremia, and carbohydrates to provide energy and prevent glycogen depletion. For oral replacement solution components to be utilized by the body, these components must be emptied from the stomach and absorbed in the intestines. Gastric emptying has been shown to be affected by volume and temperature of the fluid ingested as well as the osmolality and caloric density. Studies have shown that gastric emptying and intestinal absorption are limited to approximately two liters per hour. Of particular interest are substances, through passive or active transport through the intestinal lining, that can increase the absorption of water.
It has been well demonstrated that the addition of sugars to solutions will further enhance sodium and water absorption to an active transport mechanism. For example, a molecule of glucose, when absorbed, will transport two sodium ions with it, resulting in additional absorption of water. Other sugars such as fructose also have transport mechanisms for sodium that are independent of glucose. Thus, enhanced intestinal absorption of water is achieved with a carbohydrate-electrolyte mix and these are standard components or oral replacement solutions. However, these standard mixes do not achieve optimal absorption of water.
In addition, glutamine offers other benefits, including improved immunity and resistance to infection, maintenance of intestinal tract integrity, and restoration of muscle mass. There is no prior art disclosing these benefits or our specific beverage composition.
One particular energy supply composition was disclosed in U.S. Pat. No. 5,817,364. This patent focused on a beverage containing alpha-ketoglutaric acid. This patent specifically describes an energy supply composition, beverage or dry, suitable for use during, or after physical exertion which requires a large and rapid energy supply. In addition to the usual sugars and electrolytes contained in sports beverages, the patent includes and is expressly focused upon 0.5 to 2 grams of alpha-ketoglutaric acid. The patent specifically mentions glutamine, and it clearly states that glutamine is unstable and can only be used as a supplement in a few products. It is clear that the inventors of the patent felt glutamine would not work or be operative for the desired result. The patent focuses on alpha-ketoglutaric acid, another amino acid which is specifically different from glutamine as the desired additive.
U.S. Pat. No. 4,479,974 does discuss the use of glutamine in combination with other amino acids as a dry mix that can enhance the flavor and feel of a beverage. The dry mix they describe is purely for taste and not for the qualities needed in a sports beverage. Furthermore, the concentration of glutamine they describe, 0.2 grams in 1000 ml. (0.02%) is an order of magnitude below the glutamine compositions necessary and used herein.
It is an objective of the present invention to provide an oral replacement beverage formulation that enables one to have excellent water retention or absorption.